System and Method for Source/Drain Contact Processing

ABSTRACT

System and method for reducing contact resistance and prevent variations due to misalignment of contacts is disclosed. A preferred embodiment comprises a non-planar transistor with source/drain regions located within a fin. An inter-layer dielectric overlies the non-planar transistor, and contacts are formed to the source/drain region through the inter-layer dielectric. The contacts preferably come into contact with multiple surfaces of the fin so as to increase the contact area between the contacts and the fin.

This application is a continuation of U.S. patent application Ser. No.13/027,436, entitled “System and Method for Source/Drain ContactProcessing”, filed Feb. 15, 2011, which is a continuation of U.S. patentapplication Ser. No. 11/872,546, entitled “System and Method forSource/Drain Contact Processing”, filed Oct. 15, 2007, whichapplications are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to a system and method forforming electrical contacts, and more particularly to a system andmethod for forming electrical contacts to sections raised above asubstrate.

BACKGROUND

In the race to improve transistor performance as well as reduce the sizeof transistors, transistors have been developed that do not follow thetraditional planar format, such that the source/drain regions are notlocated in the substrate, but rather are non-planar transistors wherethe source/drain regions are located in a fin above the substrate. Onesuch non-planar device is a multiple-gate FinFET. In its simplest form,a multiple-gate FinFET has a gate electrode that straddles across afin-like silicon body to form a channel region. There are two gates, oneon each sidewall of the silicon fin. The source/drain regions arelocated in the fin, away from the substrate.

Electrical contacts to the source/drain regions have traditionallyfollowed a layout rule such that the contact is formed to connect to aportion of the top of the fin-like silicon body. Accordingly, from thislayout rule, the contact width has been either less than, or at mostequal to, the width of the fin. For example, in a device where thecontact width is 60 nm, the width of the device would necessarily beeither greater than or equal to 60 nm. In cases where the contact hasnecessarily exceeded the width of the fin in the channel region (forexample, when the FinFET width is less than 60 nm), the width of the finin the source and drain regions has been enlarged so that the width ofthe fin in these regions is larger than the width of the contact.

However, by adhering to this layout rule, a number of problems havearisen. One such problem is that, with the reduction of the contactarea, the contact resistance of the contact has risen, thereby limitingimprovements to the driving current of the device. Also, mis-alignmentof the contacts during the manufacturing process has led to variationsin the contact resistance between the device and the contacts, therebyleading to differences in resistance between various devices andreducing the overall circuit yield. Additionally, silicide formation isusually performed with an ultra shallow junction on the source/drainareas, thereby preventing improvements in the Schottky barrier height.

Accordingly, what is needed is a new contact design that allows for areduced contact resistance while also reducing mis-alignment of thecontacts during formation.

SUMMARY OF THE INVENTION

These and other problems are generally solved or circumvented, andtechnical advantages are generally achieved, by preferred embodiments ofthe present invention which provide a structure and method for formingcontacts to the source/drain regions of a non-planar semiconductordevice.

One aspect of the present invention includes a semiconductor device thatcomprises a non-planar transistor having source/drain regions located ina fin raised above the substrate. An inter-layer dielectric is locatedover the non-planar transistor, and contacts extend through theinter-layer dielectric to make contact with multiple surfaces of thefin.

Another aspect of the present invention includes a semiconductor devicethat comprises a substrate and a conductive region that extends abovethe substrate. A dielectric layer is located over the conductive region,and a contact extends through the dielectric layer to contact the topsurface of the conductive region and at least two sidewalls of theconductive region.

Another aspect of the present invention includes a semiconductor devicethat comprises a substrate and a fin raised above the substrate. Aninter-layer dielectric is located over the fin, and at least one contactis located through the inter-layer dielectric and is connected to aplurality of surfaces of the fin.

Another aspect of the present invention includes a method for forming asemiconductor device comprising forming a non-planar transistor on asubstrate, the non-planar transistor comprising a fin with source/drainregions formed therein, the fin comprising a top surface and sidewalls.An inter-layer dielectric is formed over the non-planar transistor, theinter-layer dielectric having a maximum height, and an opening is formedonly partially through the maximum height of the inter-layer dielectricso as to expose at least a portion of the top surface and at least aportion of the sidewalls of the fin. The opening is filled with aconductive material to form a contact with one of the source/drainregions, the contact in connection with the top surface and sidewalls ofthe fin.

Another aspect of the present invention includes a method for forming asemiconductor device comprising forming a conductive region over asubstrate, the conductive region comprising a first region with a firstlattice constant, a second region with a second lattice constantdifferent from the first lattice constant, and a third region oppositethe second region from the first region, the third region having thefirst lattice constant. An inter-layer dielectric is formed over theconductive region and an opening is formed through the inter-layerdielectric to expose at least three surfaces of the conductive region,the at least three surfaces forming an exposed conductive region. Theopening is filled with a conductive material to form a contact with theexposed conductive region.

Another aspect of the present invention includes a method of forming asemiconductor device comprising forming a conductive region over asubstrate, the conductive region comprising an upper surface andsidewalls, the sidewalls having a first height, the conductive regionalso comprising a first section, a second section, and a third sectioninterposed between the first section and the second section. Aninter-layer dielectric is formed over the conductive region and at leastone aperture is formed through the inter-layer dielectric to expose atleast a portion of the upper surface and at least a portion of thesidewalls, the forming the at least one aperture only exposing a portionof the first height of the sidewalls. The at least one aperture isfilled with a conductive material to form at least one contact to theconductive region, the at least one contact being in physical connectionwith the upper surface and at least a portion of two or more of thesidewalls.

Another aspect of the present invention includes a semiconductor devicecomprising a fin on a substrate, the fin having a first height from thesubstrate and comprising a top surface and a first sidewall. A contactis in physical connection with both the top surface of the fin and thefirst sidewall of the fin, the contact extending from the top surface afirst distance along the fin towards the substrate, the first distancebeing less than the first height.

Another aspect of the present invention includes a semiconductor devicecomprising a conductive semiconductor region on a substrate, theconductive semiconductor region comprising a first surface facing awayfrom the substrate and a second surface extending between the firstsurface and the substrate. A dielectric layer overlies the conductivesemiconductor region and covering the second surface, and a contactextends into the dielectric layer and in contact with the first surfaceand the second surface, wherein a first portion of the dielectric layeris located between a bottom surface of the contact and the substrate.

Another aspect of the present invention includes a semiconductor devicecomprising a fin in contact with a substrate, the fin comprising asemiconductor material. A conductive contact is making physical contactwith multiple sides of the fin, at least one of the multiple sides ofthe fin being perpendicular to the substrate, the conductive contact notin physical contact with the substrate.

An advantage of a preferred embodiment of the present invention is areduction in the contact resistance between the source/drain regions andthe contacts, which leads to greater overall device performance.Further, variations in the contact resistances because of contactmisalignment is also reduced, creating a more uniform product, and thesilicide formation does not require an ultra shallow junction, allowingfurther improvements in the Schottky barrier height.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIGS. 1-8 illustrate intermediate steps in the formation of contacts inaccordance with an embodiment of the present invention;

FIG. 9 and FIG. 9A are a perspective view and a top-down view,respectively, of contacts made to multiple surfaces of a fin containingsource/drain regions in accordance with an embodiment of the presentinvention; and

FIG. 10A and FIG. 10B are a perspective view and a top-down view,respectively, of contacts made to an upper surface and three sidewallsof a fin containing source/drain regions in accordance with anembodiment of the present invention.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the preferredembodiments and are not necessarily drawn to scale.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of the presently preferred embodiments arediscussed in detail below. It should be appreciated, however, that thepresent invention provides many applicable inventive concepts that canbe embodied in a wide variety of specific contexts. The specificembodiments discussed are merely illustrative of specific ways to makeand use the invention, and do not limit the scope of the invention.

The present invention will be described with respect to preferredembodiments in a specific context, namely a FinFet transistor. Theinvention may also be applied, however, to other semiconductor devices,particularly non-planar devices. For example, embodiments of the presentinvention may be utilized with non-planar resistors, diodes, capacitors,fuses and the like.

With reference now to FIG. 1, there is shown a preferredsemiconductor-on-insulator (SOI) substrate, although other substrates,such as bulk silicon, strained SOI, and silicon germanium on insulator,could alternatively be used. The preferred semiconductor-on-insulatorsubstrate includes a substrate 101, an insulator layer 103, and asemiconductor layer 105. The substrate 101 is preferably silicon.

The insulator layer 103 may be formed from any dielectric or insulator,and is preferably comprised of silicon oxide or silicon nitride or astructured combination of both. The insulator layer 103 may have athickness in the range of about 100 angstroms to about 3,000 angstroms,although it is understood that thinner or thicker thicknesses may beused.

The semiconductor layer 105 may be formed from an elementalsemiconductor such as silicon, an alloy semiconductor such assilicon-germanium, or a compound semiconductor such as gallium arsenideor indium phosphide. The semiconductor layer 105 is preferably silicon.The thickness of the semiconductor layer 105 may be in the range ofabout 200 angstroms to about 5,000 angstroms. In an alternateembodiment, bulk semiconductor substrates such as a bulk siliconsubstrate may also be used. Preferably, the substrate semiconductorlayer 105 is a p-type semiconductor, although in other embodiments, itcould be an n-type semiconductor.

FIG. 2 illustrates the formation of a fin 201 from the semiconductorlayer 105. The fin 201 may be formed by depositing a mask material (notshown) such as a photoresist material and/or a hardmask over thesemiconductor layer 105. The mask material is then patterned and thesemiconductor layer 105 is etched in accordance with the pattern formingthe fin 201 as illustrated in FIG. 2.

FIG. 3 illustrates the formation of a gate dielectric layer 301 over thefin 201. The gate dielectric layer 301 may be formed by thermaloxidation, chemical vapor deposition, sputtering, or any other methodsknown and used in the art for forming a gate dielectric. Depending onthe technique of gate dielectric formation, the gate dielectric 301thickness on the top of the fin 201 may be different from the gatedielectric thickness on the sidewall of the fin 201.

The gate dielectric 301 may comprise a material such as silicon dioxideor silicon oxynitride with a thickness ranging from about 3 angstroms toabout 100 angstroms, preferably less than about 10 angstroms. The gatedielectric 301 may alternatively be formed from a high permittivity(high-k) material (e.g., with a relative permittivity greater than about5) such as lanthanum oxide (La₂O₃), aluminum oxide (Al₂O₃), hafniumoxide (HfO₂), hafnium oxynitride (HfON), or zirconium oxide (ZrO₂), orcombinations thereof, with an equivalent oxide thickness of about 3angstroms to about 100 angstroms, and preferably 10 angstroms or less.

FIG. 4 illustrates the formation of gate electrode layer 401. The gateelectrode layer 401 comprises a conductive material and may be selectedfrom a group comprising of polycrystalline-silicon (poly-Si),poly-crystalline silicon-germanium (poly-SiGe), metallic nitrides,metallic silicides, metallic oxides, and metals. Examples of metallicnitrides include tungsten nitride, molybdenum nitride, titanium nitride,and tantalum nitride, or their combinations. Examples of metallicsilicide include tungsten silicide, titanium silicide, cobalt silicide,nickel silicide, platinum silicide, erbium silicide, or theircombinations. Examples of metallic oxides include ruthenium oxide,indium tin oxide, or their combinations. Examples of metal includetungsten, titanium, aluminum, copper, molybdenum, nickel, platinum, etc.

The gate electrode layer 401 may be deposited by chemical vapordeposition (CVD), sputter deposition, or other techniques known and usedin the art for depositing conductive materials. The thickness of thegate electrode layer 401 may be in the range of about 200 angstroms toabout 4,000 angstroms. The top surface of the gate electrode layer 401usually has a non-planar top surface, and may be planarized prior topatterning of the gate electrode layer 401 or gate etch. Ions may or maynot be introduced into the gate electrode layer 401 at this point. Ionsmay be introduced, for example, by ion implantation techniques.

FIG. 5 illustrates the patterning of the gate dielectric 301 and thegate electrode layer 401 to form a gate stack 501 and define a firstsection of the fin 503, a second section of the fin 505, and a channelregion 507 located in the fin 201 underneath the gate dielectric 301.The gate stack 501 may be formed by depositing and patterning a gatemask (not shown) on the gate electrode layer 401 (see FIG. 4) using, forexample, deposition and photolithography techniques known in the art.The gate mask may incorporate commonly used masking materials, such as(but not limited to) photoresist material, silicon oxide, siliconoxynitride, and/or silicon nitride. The gate electrode layer 401 and thegate dielectric layer 301 may be etched using plasma etching to form thepatterned gate stack 501 as illustrated in FIG. 5.

FIG. 6 illustrates the completion of the device 600 through theformation of spacers 601, source/drain regions 603, and silicidecontacts 605. The spacers 601 may be formed on opposing sides of thegate stack 501. The spacers 601 are typically formed by blanketdepositing a spacer layer (not shown) on the previously formedstructure. The spacer layer preferably comprises SiN, oxynitride, SiC,SiON, oxide, and the like and is preferably formed by methods utilizedto form such a layer, such as chemical vapor deposition (CVD), plasmaenhanced CVD, sputter, and other methods known in the art. The spacers601 are then patterned, preferably by anisotropically etching to removethe spacer layer from the horizontal surfaces of the structure.

Source/drain regions 603 are formed in the first section of the fin 503and the second section of the fin 505 by implanting appropriate dopantsto complement the dopants in the fin 201. For example, p-type dopantssuch as boron, gallium, indium, or the like may be implanted to form aPMOS device. Alternatively, n-type dopants such as phosphorous, arsenic,antimony, or the like may be implanted to form an NMOS device. Thesesource/drain regions 603 are implanted using the gate stack 501 and thegate spacers 601 as masks. It should be noted that one of ordinary skillin the art will realize that many other processes, steps, or the likemay be used to form these source/drain regions 603. For example, one ofordinary skill in the art will realize that a plurality of implants maybe performed using various combinations of spacers and liners to formsource/drain regions having a specific shape or characteristic suitablefor a particular purpose. Any of these processes may be used to form thesource/drain regions 603, and the above description is not meant tolimit the present invention to the steps presented above.

In a preferred embodiment the source/drain regions 603 may be formed soas to reduce the Schottky barrier height of subsequent contacts(discussed below with respect to FIGS. 9A-B and 10A-B) with thesource/drain regions 603. For example, the dopants for the source/drainregions 603 may be implanted through a segregated doping method.Alternatively, an ultrathin insulator layer (not shown) may be formedover the source/drain regions 603 and the dopants may be implantedthrough the ultrathin insulator layer.

In another embodiment the source/drain regions 603 are formed so as toimpart a strain on the channel region 507. In this embodiment, the firstsection 503 of the fin 201 and the second section 505 of the fin 201 areremoved through a process such as a wet etch. The first section 503 andthe second section 505 may then be regrown to form a stressor that willimpart a stress to the channel region 507 of the fin 201 locatedunderneath the gate stack 501. In a preferred embodiment wherein the fin201 comprises silicon, the first section 503 of the fin 201 and thesecond section 505 of the fin 201 are etched while using the gate stack501 or spacers 601 to prevent etching of the channel region 507. Afterremoval of the first section 503 of the fin 201 and the second section505 of the fin 201, these sections may then be regrown through aselective epitaxial process with a material, such as silicon germanium,that has a different lattice constant than the silicon. The latticemismatch between the stressor material in the source and drain regions603 and the channel region 507 will impart a stress into the channelregion 507 that will increase the carrier mobility and the overallperformance of the device. The source/drain regions 603 may be dopedeither through an implantation method as discussed above, or else byin-situ doping as the material is grown.

After the source/drain regions 603 have been formed, an optionalsilicide process can be used to form silicide contacts 605 along one ormore of the top and sidewalls of the fin 201 over the source and drainregions 603. The silicide contacts 605 preferably comprise nickel,cobalt, platinum, or erbium in order to reduce the Schottky barrierheight of the contact. However, other commonly used metals, such astitanium, palladium, and the like, may also be used. As is known in theart, the silicidation may be performed by blanket deposition of anappropriate metal layer, followed by an annealing step which causes themetal to react with the underlying exposed silicon. Un-reacted metal isthen removed, preferably with a selective etch process. The thickness ofthe silicide contacts 605 is preferably between about 5 nm and about 50nm.

Alternatively, instead of silicide contacts, a metal layer (not shown)may be formed along one or more of the top and sidewalls of the fin 201over the source and drain regions 603. The metal layer preferablycomprises aluminum, nickel, copper, or tungsten in order to lower theSchottky barrier height of the contact.

FIG. 7 is a cross sectional view of the structure of FIG. 6 taken alongthe 7-7′ line and which illustrates an optional contact etch stop layer(CESL) 701 formed over the device 600 for protection during subsequentprocess steps. The CESL 701 may also be used as a stressor to form astress in the channel region 507 of the device 600. The CESL 701 ispreferably formed of silicon nitride, although other materials, such asnitride, oxynitride, boron nitride, combinations thereof, or the like,may alternatively be used. The CESL 701 may be formed through chemicalvapor deposition (CVD) to a thickness of between about 20 nm and about200 nm, with a preferred thickness of about 80 nm. However, othermethods of formation may alternatively be used. Preferably, the CESL 701imparts a tensile strain to the channel region 507 of the fin 201 for anNMOS device and imparts a compressive strain to the channel region 507of the fin 201 for a PMOS device.

FIG. 8 illustrates the formation of an inter-layer dielectric (ILD) 801over the device 600. For the sake of clarity the CESL 701 illustrated inFIG. 7 is not shown, and the silicide contacts 605 and source/drainregions 603 have been merged into one area shown as the silicidecontacts 605. The ILD 801 may be formed by chemical vapor deposition,sputtering, or any other methods known and used in the art for formingan ILD 801. The ILD 801 typically has a planarized surface and may becomprised of silicon oxide, although other materials, such as high-kmaterials, could alternatively be utilized. Preferably, the ILD 801 isformed so as to impart a strain to the channel region 507 of the fin201, which will increase the overall performance of the device 600.

FIG. 9A illustrates the formation of contacts 901 through the ILD 801 tothe silicide contacts 605. Contacts 901 may be formed in the ILD 801 inaccordance with known photolithography and etching techniques.Generally, photolithography techniques involve depositing a photoresistmaterial, which is masked, exposed, and developed to expose portions ofthe ILD 801 that are to be removed. The remaining photoresist materialprotects the underlying material from subsequent processing steps, suchas etching. In the preferred embodiment photoresist material is utilizedto create a patterned mask to define contacts 901. The mask is patternedto subsequently form openings that are wider than the width of the fin201. Additional masks, such as a hardmask, may also be used.

The etching process may be an anisotropic or isotropic etch process, butpreferably is an anisotropic dry etch process. In a preferredembodiment, the etch process is continued until an upper surface 903 ofthe fin 201 containing the source/drain regions 603 and at least aportion of the sidewalls of the fin 201 are exposed, thereby exposing atleast three surfaces of the fin 201 (portions of the top surface andportions of at least two sidewalls).

Contacts 901 are then formed so as to contact the exposed surfaces ofthe fin 201. In this embodiment each contact 901 is formed so as to bein contact with multiple surfaces of the fin 201. In a preferredembodiment the contacts 901 are formed so as to be in contact with atleast three surfaces of the fin 201, although a larger or smaller numberof surfaces could alternatively be contacted. This allows for a largerarea of contact between the silicide contacts 605 and the contact 901than contacts that only contact the top surface of the fin 201.Accordingly, the contact resistance of the device may be reduced. Thisembodiment also has the advantage of reducing variations in the contactresistances due to mis-alignments of the contacts 901, since there ismore leeway for variation when the width of the contacts 901 are largerthan the width of the fin 201.

The contacts 901 may comprise a barrier/adhesion layer (not shown) toprevent diffusion and provide better adhesion between the contacts 901and the ILD 801. In an embodiment, the barrier layer is formed of one ormore layers of titanium, titanium nitride, tantalum, tantalum nitride,or the like. The barrier layer is preferably formed through chemicalvapor deposition, although other techniques could alternatively be used.The barrier layer is preferably formed to a combined thickness of about50 Åto about 500 Å.

The contacts 901 may be formed of any suitable conductive material, suchas a highly-conductive, low-resistive metal, elemental metal, transitionmetal, or the like. In an exemplary embodiment the contacts 901 areformed of tungsten, although other materials, such as copper, couldalternatively be utilized. In an embodiment in which the contacts 901are formed of tungsten, the contacts 901 may be deposited by CVDtechniques known in the art, although any method of formation couldalternatively be used.

FIG. 9B illustrates a top-down view of the device 600 formed by theprocess described above with reference to FIG. 8A. As noted, in thisembodiment, the contacts 901 are formed to have a larger contact areathan previous contacts. Further, the width of the fin 201 at the area ofcontact may be smaller than the contacts 901, and the fin 201 does nothave to be widened in the area of the contacts 901 in order to meetdesign rules.

FIG. 10A illustrates another embodiment in which the contacts 901 are inconnection with multiple sides of the fin 201. However, in thisembodiment, the contacts 901 are formed so as to contact not only thetop of the fin 201 and at least two of the sidewalls of the fin 201, butconnect to the top of the fin 201 and at least three of the sidewalls ofthe fin 201. In this embodiment the etch used to form the openings forthe contacts 901 continues beyond the upper surface 903 of the fin 201until at least a portion of three sidewalls of the fin 201 aresubstantially exposed, and potentially until at least a portion of theinsulator layer 104 has also been substantially exposed. Accordingly,when the material for the contacts 901 is deposited or else formed inthe openings, the contact 901 will be formed in connection with at leastfour surfaces of the fin 201, including the top of the fin 201 and atleast three of the sidewalls of the fin 201.

FIG. 10B illustrates a top-down view of the embodiment described abovewith respect to FIG. 10A. As previously indicated, the contacts 901 arein connection with at least four surfaces of the fin 201, which allowsfor a larger contact area between the contacts 901 and the silicidecontacts 605. This larger contact area would allow for a reduction ofthe width of the fin 201 while preventing a subsequent rise in thecontact resistance due to a reduced contact area.

In a preferred embodiment of the present invention, the multi-sidedcontacts 901 are preferably formed on a device 600 that comprises eithera strained channel region or a reduced Schottky barrier height betweenthe source/drain regions 603 and the contacts 901, or both. Preferably,the Schottky barrier height may be reduced through the methods describedabove with reference to FIG. 6. The strained channel may be formedthrough a suitable strained process, preferably including one or more ofthe strained processes described above. These processes preferablyinclude SiGe Source/Drain epitaxial growth (described above with respectto FIG. 6), CESL (described above with respect to FIG. 7), and ILD(described above with respect to 8).

Although the present invention and its advantages have been described indetail, it should be understood that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of the invention as defined by the appended claims. For example,there are multiple methods for the deposition of material as thestructure is being formed. Any of these deposition methods that achievesubstantially the same result as the corresponding embodiments describedherein may be utilized according to the present invention.

Moreover, the scope of the present application is not intended to belimited to the particular embodiments of the process, machine,manufacture, composition of matter, means, methods and steps describedin the specification. As one of ordinary skill in the art will readilyappreciate from the disclosure of the present invention, processes,machines, manufacture, compositions of matter, means, methods, or steps,presently existing or later to be developed, that perform substantiallythe same function or achieve substantially the same result as thecorresponding embodiments described herein may be utilized according tothe present invention. Accordingly, the appended claims are intended toinclude within their scope such processes, machines, manufacture,compositions of matter, means, methods, or steps.

1. A semiconductor device comprising: a fin on a substrate, the fin having a first height from the substrate and comprising a top surface and a first sidewall; and a contact in physical connection with both the top surface of the fin and the first sidewall of the fin, the contact extending from the top surface a first distance along the fin towards the substrate, the first distance being less than the first height.
 2. The semiconductor device of claim 1, further comprising a second sidewall, the contact being in physical connection with the second sidewall.
 3. The semiconductor device of claim 2, further comprising a third sidewall, the contact being in physical connection with the third sidewall.
 4. The semiconductor device of claim 1, wherein the fin is part of a non-planar transistor.
 5. The semiconductor device of claim 1, wherein the fin comprises a silicide, wherein the contact is in physical connection with the silicide.
 6. The semiconductor device of claim 1, further comprising an etch stop layer over the fin, the contact extending through the etch stop layer.
 7. The semiconductor device of claim 1, wherein the fin comprises a metal layer, wherein the contact is in physical connection with the metal layer.
 8. A semiconductor device comprising: a conductive semiconductor region on a substrate, the conductive semiconductor region comprising a first surface facing away from the substrate and a second surface extending between the first surface and the substrate; a dielectric layer overlying the conductive semiconductor region and covering the second surface; and a contact extending into the dielectric layer and in contact with the first surface and the second surface, wherein a first portion of the dielectric layer is located between a bottom surface of the contact and the substrate.
 9. The semiconductor device of claim 8, wherein the conductive semiconductor region further comprises a third surface extending between the first surface and the substrate, the third surface in physical contact with the contact.
 10. The semiconductor device of claim 9, wherein the conductive semiconductor region further comprises a fourth surface extending between the first surface and the substrate, the fourth surface in physical contact with the contact.
 11. The semiconductor device of claim 8, further comprising a source region, a drain region, and a channel region within the conductive semiconductor region, the channel region located between the source region and the drain region.
 12. The semiconductor device of claim 11, wherein the source region and the drain region have a first lattice constant and the channel region has a second lattice constant different from the first lattice constant.
 13. The semiconductor device of claim 11, further comprising an etch stop layer over the conductive semiconductor region, the etch stop layer applying stress to the channel region.
 14. A semiconductor device comprising: a fin in contact with a substrate, the fin comprising a semiconductor material; and a conductive contact making physical contact with multiple sides of the fin, at least one of the multiple sides of the fin being perpendicular to the substrate, the conductive contact not in physical contact with the substrate.
 15. The semiconductor device of claim 14, wherein the multiple sides of the fin comprises two sides of the fin.
 16. The semiconductor device of claim 14, wherein the multiple sides of the fin comprises three sides of the fin.
 17. The semiconductor device of claim 14, wherein the multiple sides of the fin comprises four sides of the fin.
 18. The semiconductor device of claim 14, further comprising a gate stack overlying a portion of the fin.
 19. The semiconductor device of claim 14, further comprising an interlayer dielectric over the fin, the conductive contact extending into the interlayer dielectric.
 20. The semiconductor device of claim 14, wherein the fin comprises a silicide material in physical contact with the conductive contact. 